Elastomeric materials have been formed into countless different articles suitable for use in many applications, such as surgical gloves, examining gloves, condoms, catheters, balloons, tubing, and the like. Elastomeric materials have been found particularly suitable for such applications due to their physical characteristics. For example, elastomeric materials, in addition to having good elastic properties, exhibit good strength characteristics and may be produced so as to be impermeable not only to aqueous solutions, but also to many solvents and oils.
Elastomeric materials are typically tacky to the touch and present a somewhat sticky surface. Tackiness of the surface of the article often renders manufacture and use of the article difficult, at best. For example articles such as gloves, catheters, or balloons may stick to formers during manufacture and to themselves and each other during packaging and shipping. In addition, elastomeric articles often feel sticky to human skin. For example, elastomeric articles such as gloves may be difficult to slip over the hand during donning due to tackiness at the glove surface. Historically, the most common process for decreasing surface tackiness of an elastomeric article has been the addition of a powder to the article's surface. The powder acts as a buffer or barrier between the surface of the article and other materials to make the elastomeric article feel more slippery. While powder on the article surface is acceptable for some applications, powders may not be desired in certain applications, such as surgical or other clean-room type applications.
As a result, powder free coatings have been developed for elastomeric articles in an attempt to provide the articles with increased slip at the surface. For instance, hydrophilic coatings such as hydrophilic hydrogel polymer systems have been used to form coatings on elastomeric materials in an attempt to decrease surface friction. In order to form the thin coatings on the elastomeric articles, such polymer systems have often been cured in the presence of a formaldehyde based crosslinking agent and a catalyst, such as a paratoluene sulfonic acid catalyst.
Problems have been encountered with these systems, however. For instance, highly hydrophilic coatings absorb a great deal of water, causing substantial volume changes in the coating during hydration and drying. This may lead to delamination and peeling of the coating from the glove surface. Additionally, highly hydrophilic polymers are often quite rigid in the dry state. This may lead to cracks forming in the coating, which may also lead to delamination of the coating from the surface of the elastomeric article.
In addition, the chemicals used in forming the coatings, for example, the formaldehyde-based cross linking agents and toluene-based catalysts, may present waste disposal problems due to their toxicity.
As such, a need currently exists for an elastomeric article with a suitable surface coating which may provide the desired surface characteristics as well as avoid peeling or delamination of the coating from the article surface. Moreover, a need exists for an elastomeric article which does not incur waste disposal problems due to the presence of formaldehyde-based cross-linking agents.